Absorption machine



Nov. 15, 1932. E. ALTENKIRCH ABSORPTION IACHINE Original Filed June 8; 1929 2 sheets-sheet 1 NOV. 15, 1932. KIRCH 7 1,887,909

ABSORPTION MACHINE Original Filed June 8, 1929 2 Sheets-Sheet 2 Patented Nov. 15, 1932 UNITED STATES PATENT orrlcs EDMUND .ALTENKIBCH, OF NEUENHAGEN, NEAR BERLIN, GERMANY, ASSIGNOR TO SIEMENS-SCH'UCKERTWERKE AKTIENGESELLSCHAI'T, OF BEBLIN-SIEHENBSTADT, GERMANY, A CORPORATION" OF GERMANY ansonr'rron monmn Original application filed June s, 1929, Serial no. asaass, and in Germany June ie, 1928. Divided and this application filed October 9, 1930. Serial No. 487,465

7 My invention relates to absorption machines.

It is known in the art to construct continuously operating absorption machines, part cularly absorption refrigerating machines 1n such a manner that the difierences of pressure between the evaporator and the absorber on the one hand and between the generator and the condenser or resorber on the other hand are more or less equalized by admixing a neutral gas to the gaseous working medium in the evaporator and absorber. In the known tion, but, in which in contrast to t e hitherto known absorption machines of that kind, the development of the gaseous working medium in the generator also takes p1aceat least partly-in the presence 1 of a neutral gas. Now the absorption solution circulating through the resorber and the evaporator belongs to another range of concentration than the absorption solution circulating through the generator and absorber. The difference between the present invention and the known absorption machines with admixture of a neutral gas may, therefore, be expressed as follows: Whilst inthe known absorption machines the absorption solution from which the gaseous working medium evaporates into the neutral gas has a different concentration or is within a different range of concentration than the absorption solution by which the workmg medium is absorbedput of the gas mixture, the absorption mixture is according to my invention in both cases within the same temperatures and the partial range of concentration. But -'the range of pressure zone, in which the development 0 the gaseous workingmedium in the generator from the absorption solution into the neutral gas and its absorption from the gas mixture takes place, are different from one another, The

advantage obtained by the admixture of neutral gas in the generator, is in the first place as follows: As it can easily be arranged that in the mixture of gaseous working medium and neutral gas entering the generator the partial pressure of the gaseous working medi-.

um is verylow, it becomes possible to obtain by such means a particularly extensive dogasification of the absorption solution in the generator, and without having to raise the final temperature of the generator as high as is necessary with generators without an admixture of gas. The extensive de-gasification of the absorption solution is of great importance for a good absorbing action in the absorber. The reduction of the final temperature of the generator is again useful on account of the danger of decomposition of the gaseous working medium (e. g. ammonia) at high temperatures, such as are ordinarily necessary particularly with air-cooled ab.- sorption machines.

The useful efiect obtained by admixin an indifierent gas in the generator mani ests itself particularly, when the generator together with one or several other vessels of the absorption machine, in which gaseous working medium is absorbed by an absorption solution, forms a circulation system for the indifferent gas or for the mixture of indifferent gas with the gaseous working medium. The resorber is the first vessel to come into consideration to form part of' this gas-circulation system. If, however, several generators and several absorbers are employed, a generator and an absorber may be connected together to form a circulation system for gasmixture. It is'also possible to connect one or more generators with a. resorber and one or more absorbers as to form a common system for the circulation of gas mixture. The efiect is particularly strong, if the gas mixture is made tocirculate in connterflow to the absorption solution, so for instance, the gas mixture deprived as much as possible of gaseous working medium in the resorber is first brought into contact with the absorption solution leaving the absorber.

The circulation of the asmixture between the generator and the a sorber or between the generatorand the resorber, may easily be brought about by the upward pressure roduce o facilitate this circulation, the absorber and the resorber are disposed at'ahigher level than the enerator and as an' indifferent gas for admixing, particularly a gas heavier than the gaseous working medium should be emplo ed.

Further detai s, possibilities ofconstruction -and advantages of the invention are contained in the following description, and

,in the accompanying drawings, which illustrate the invention, in part schematically, and part in a form approaching the actual construction. From all figures of the draw- 1n .will be seen the manner in which the individual vessels are connected with one another by means of a liquid iping and gas piping. The arrowed dashot lines repre-' Fig. 2 is the diagram of an absorption refri erating machine, in which a generator and a resorber, a second generator and an absorber and a second absorber and an evaporator are connected together respectively in pairs, each of the airs mentioned forming a gas mixture circu ation system.

Fig. 3 is a diagram of an absorption refrigerating machine with a generator, an absorber, two resorbers and two 'evaporators,

.in which one of the resorbers is connected with the generator, the other resorber with one of the two evaporators, and the other evaporator with the absorber, in such a manner as to form three circulation systems for the gas mixture. I

Fig. 4 is the diagram of an absorption refrigeratin machine with two generators, two absor rs, one resorber and one evaporator in which the evaporator is connected with one of the two generators and with both absorbers so as to constitute a common gas- 'mixture circulation system, while the resorber and the other generator are free of indifferent gas.

Fig. 5 is the diagram of an absorption machine suitable for the production of heat at a high temperature with one generator, one absorber, one resorber and one evaporator,

by the heating in the generator.

i. e. with the same constituent parts as in Fig. 1, but in which all the vessels are on the one hand connected with one another to form a single liguid circulation system and on the other ban to form a single, closed gas-mixture circuit.

Fig. 6 isthe diagram of an absorption refrigerating. machine with one generator, two absorbers, one resorber and one evaporator, in which the generator is connected with the resorber and one ofthe two absorbers on the one'hand, and the other absorber with the evaporator on the other hand, in such a man ner that each of the groups forms a closed gas-mixture circulation system, and

Fig. 7 shows the absorption refrigerating machine, represented diagrammatically in Fig. 2. It illustrates the arrangement of the various vessels and connecting pi s substantially in the form of a practlca apparatus.

The essence of the invention is simple to explain with reference to the schematic Fig. 1. In that figure the generator is indicated by K, the absorber by A, the resorber by R and the evaporator by E. The liquid circulation systems are indicated by thin lines, and

gas mixture circulation systems by thicker dot-and-dash lines. The direction of circulation is shown by arrows. Let us assume, for example, that the solvent consists of sulphuric acid, the working medium of water,

the neutral gas in the generator and resorber of nitrogen, and that in the evaporator and absorber of hydrogen, and further that the sulphuric acid solution, deprived of water to a great extent, flowin from the generator K to the absorber A exc anges its heat with the solution enriched with working medium and flowing from the absorber to the generator. We also assume that the very watery solution, flowing from the resorber to the evaporator exchanges heat with the solution coming back from the evaporator to the resorber. For simplicity, the heat exchange has not been indicated in the drawings; but might be inferred from the close proximity of the pertaining lines.

The absor tion machine schematically illustrated in ig, 1 operates as follows:

When'heat is imparted to the aqueous sulphuric acid solution in the generator K, steam develops into the admixed nitrogen. The sulphuric acid, which has become more concentrated owing to the evaporation of water, then passes into the absorber A. The as mixture containing nitrogen becomes eated through coming into contact with the absorption solution in the generator K and also becomes 1i hter owing to the steam it now contains. t therefore rises into theresorber R where it gives up to the sulphuric acid solution coming from the evaporator E the steam which it took from the generator.

The absorption heat produced is carried oil by cooling water or air. The gas-mixture V more or less deprived of steam returns to the generator K, whereas the sulphuric acid, weakened by the water it has taken up, passes into the evaporator E, where it gives up to the admixedhydrogen the steam it contains and thereby produces useful refrigeration. In doing so the gas mixture becomes heavier and descends into the'absorber A, where the steam is absorbed by the concentrated sulphuric acid coming from the generator K; the heat produced thereby being here also carried away by cooling water or air. Thegas mixture which is now freed from steam and hasbeen heated in the absorber rises a ain into the evaporator. In all vessels, the a sorption solution and the gas mixture flow, as shown by arrows, in counterflow to each other.

The total pressure in the two gas circulation systems may be different, or may be the same. I If it is diflerent, the difference of pressure is maintained in a known manner, for instance, by means of ii uid columns. For example in case of an un erpressure in the absorber the latter would be placed higher than the generator, and if there is an underpres sure in the evaporator, it would be placed higher than the resorber.

It simplifies matters, if in the difierent gas mixture circulation systems neutral gas of the same kind is used for admixing, and the total pressure is maintained at an equal value in both systems. Itis also in this case possible to produce without difliculty by known means the circulation of the gas mixture in each of the two systems.

The gaseous working medium is absorbed in theresorber from the gas mixture by the solution at a partial pressure corresponding to the temperature of the cooling means. From the solution it again eva orates into neutral gas in the same range 0 concentration in a zone of a lower partial pressure. It has hith erto been assumed that the gaseous working means is developed in the generator at a pressure corresponding to the partial pressure of the resorber and was fed to the neutral gas. The invention however ains considerably in importance if in the a third (higher) pressure zone or partial pressure zone is provided, in which gaseous working medium is developed and liquefied, the latter for instance through absorption in a resorber. This zone of highest pressure may be used with or without indiflerent gas-1 The arrangement of the third zone of higher pressure permits a considerable reduction of the heat supplied-to absorption machines, which are to produce cold. This reduction is, for instance, of advantage where the absdrption machine is operated with waste heat, and where low useful temperatures are uired in spite of'the reduced heat supply. ith the assumption that gaseous working rption machine a medium is generated in the presence of an indifferent gas, this problem may be solved by making the partial pressure, at which the working medium evaporates from the solution of the same range of concentrationinto the indifferent gas, higher than the partial highest pressure. The generation and abgaseousworking medium, I

sorption of the therefore, takes place here in two separate pressure sta es. For this purpose, besides an evaporator and a resorber R, two generators K and K as well as two absorbers A and A are ment, it is made medium partial pressure zone, instead of going into a condenser the absorber A through the agency of the indifferent gas, into which it was developed when being generated. In the absorber A it is reabsorbed in presence of indifferent, gas at a medium temperature and a medium partial pressure. As the partial pressure in the absorber A corresponds to the partial pressure inthe enerator K and is, therefore, considerably V 'gher than in the absorber A (which is connected with the generator K so as toform a liquid circulation system, and

provided. With this arrangepossible for the working medium generated in the generator K in the or resorber, to pass into the partial pressure of which corresponds to i the partial pressure in the evaporator-E), the solution in A riched with working medium.

Consequently, the temperature in the generator K operating at a still higher partial pressure can be considerably reduced, without impairing the obtainable temperature of the refrigeration output. In the example, upon which Fig. 2 is based, there .are three circuits of absorption solutions, in which according to the invention gaseous working medium is developed from an absorption solution within a range of temperatures and a sure zone into an indifferent gas, and is rewill be considerably more enpartial pres absorbed by an absorption solution of the same range of concentration from a mixture of indifferent gas and gaseous working medium within another range of temperature and another partial pressure zone. This takes place in the circuit between the generator K and the absorber A as well as between the generator K and the absorber A and finally tween the resorber R and the evaporator E. If the object of the plant, is not to produce cold, but heat of high temperature, then a considerabl higher temperature of the heat output can be obtained with the last arrange ment described above, than with the devices hitherto known. It is only im ortant that there should be a generator, in w ich the partial pressure, at which the gaseous working medium is developed from the solution of the same concentration range into the indifierent gas, is higher than the partial pressure at which the working medium is absorbed from the gas mixture by'the solution, but is at the same time lower than the pressure or partial pressure, at which the liquefying or resorption preceding the evaporation or de-gasification takes place in the working medium circuit. An arrangement of this'kind is schematically illustrated in Fig. 5, and will be described later. i

Fig. 3 shows an example of an absorption refrigerating machine, in which the generator is connected with a resorber, a second resorber with an evaporator, and a second evaporator with the absorber, in such a manner that in each case a closed gas-mixture circuit is formed. The liquid circuits between the two resorbersand the pertaining evaporators are here connected with one another in such a manner, that the absorption solution circulating between two temperature ranges, or at least a part of this solution, passes through all the three partial pressure zones. Let us assume that in the example schematically illustrated by Fig. 3 the working medium consists of amonia, the solvent of water, and the indifferent gas in all the three gas-mixture circuits of nitrogen. The gas-mixture circulation systems may be provided with interconnections by means of which the total pressure in all the systems are brought to the same value. These interconnections are for simplicity not shown in Fig. 3. The ammonia developed in the' generator K through outside heat supply at a high temperature, passes by means of a gas-mixture circuit into the resorber R. In the latter the ammonia is absorbed by an absorption solution, which passes in the first place into the evaporator E which in turn is connected with the resorber R throgh a gas-mixture circuit.

The ammonia which has assumed the form of gas in the evaporator E is re-absorbed by the solution flowing through the resorber R- This solution is in a condition to do so, since from the evaporator. E it passes into the evaporator E where, at a low partial pressure of the ammonia, it is deprived of gas to a great extent by circulationof as-mixture which leads through the absor r A so that the solution enters the resorber R, at a comparatively weak concentration. From the resorber R the solution returns into the resorber R where it obtains under the partial pressure produced in the generator K, the strong concentration of ammonia, which enables it to produce cold, already in the evaporator E at the same medium partial pressure also prevailing in the resorber R In the entire absorption machine aconsiderably lower total pressure may prevail as a result of the admixture of the indifierent gas in all chambers, than would correspond to the vapor pressure of the pure ammonia. If a high total pressure is, however, applied in the absorption machine, it may be necessary to maintain the quantity of the solution, circulating between the resorber R and the evaporator E smaller than the quantity of the solution, circulating between the resorber R and the evaporator E The manner in which this may be simply done is shown in F. g. 3, namely by means of a shunt running from the liquid pipe connecting the vessels R and R to the liquid pipe connecting E and E By means of thisshunt it is possible to return a portion of the absorption solution into the evaporator E already when it leaves the resorber R whereas the other portion of the solution traverses besides the said two vessels also the resorberB- and the cle-gasifier E By combining several liquid circulating circuits it is possible 'to go still further, for instanc E, by providing similarly as for the arrangement according to Fig; 2, two absorbers with separate liquid circulating circuits, but by combining in this case the liquid circulating circu't of one of the absorber systems with the liquid circulating circuit of the resorber system. Such a case is illustrated in Fig. 4. A liquid circulating circuit connects here the generator K of the medium partial pressure zone to the absorber A of the lowest partial\ pressure zone, whereas a second liquid circulating circuit traverses the generator K of the highest pressure zone, the evaporator E, the resorber R and the absorber A of the medium partial pressure zone. In th's'case the quantity of the solution circulating in the resorber system (resorber R and evaporator E) must agree with the quantity of the absorption solution which circulates in one of the two absorber systems (absorber A and generator K between the medium partial pressure zone and the higher pressure zone. It is thus ossible to deliver the weakened solution, comng from the evaporator directly to the generator, by inserting one or several heat exchangers and by supplying the resorber with the absorption liquid which comes from the absorber A operating at a medium partial pressure, whereas the circulation of the solution between the generator K working at a medium partal pressure and the absorber A, workin at a low partialpressure remains separate It is thus feasible to largely adapt the different natures of the circulating quantities to the working conditions in a simple manner.

In the case of absorption refrigerating machine, shown schematically in Fig. 4, no indifferent gas has been admixed to the higher pressure zone in the generator 'K; 'as well rator E and absorber A and for the medium partial pressure zone generator K and absorber A This gas mlxture circuit is traceable from absorber A to the circuit, which is traceable from the absorber A, to the evaporator E, from there to the generator K and finall through the absorber A back to the absor r A The absorption solution flows, as the direction of the arrows shows, in the range ofthe stronger concentration, from resorber Rinto evaporator E, from there into the generator K then into absorber A and finally back into resorber R. A perfect operation of this absorption refrigerating machine presupposes, as a matter of course, a good exchange of heat between the absorption solutions as well as between the. gas mixtures, which circulate between the warm and cold parts of the machine.

The greatest sim licity of the liquid circulation as well as o the gas mixture circulationis obtained by combining all individual closed liquid circuits in the absorption ma chine to a single common closed liquid circuit, and likewise all individual closed gas mixture circuits to a single common closed gas mixture circuit. An absorption machine of this kind which is utilized for the production of heat of a higher temperature fromheat supplied at a lower temperature and in which all chan es of the condition of ag gation are broug t about is represented in. ig. 5. The heat supplied from outside is transmitted here at a mean temperature to the generator K and to the evaporator E. The absorption solution, deprived bf the driving medium flows, as the arrows show, at first into the resorber R and is there brought together with the gas mixture which is enriched by Igaseous working medium in the generator By the absorptionof the working medium from the gas mixture .in the re- I sorber-R, heat of. high temperature is produced which can be delivered to the outside for useful purposes. The gas mixture in the resorber R, partially freed of the working medium passes now into the absorber A, cooled down by low temperatures, where, in a low partial pressure zone of the working me-.

dium, the solution enriched by the working medium in the resorber R, will be still further enriched from-the gas mixture. The solution is then returned at a mean temperature to the generator K for the purpose of renewed development of a gaseous working medium. The gas mixture in the absorber A, freed to a great extent of the working medium passes into the evaporator E, and

through the heat of a mean -tem erature' brings about a thorough degassing o the absorption solution in the latter. Thegreatly impoverished absorption solution will be thereby capable when reaching resorber R, to absorb therein working medium from the rich gas mixture supplied from generator K, and develop heat-(heat withdrawal) as far down as the middle partial pressure.

In order that a comparatively great amount 7 V of heat of high temperature may be produced with the-least possible extraction of heat at low temperature supplied from outside itis indispensable that the liquid as well as ,the gas mixture from closed circuits, wherever necessary, that they exchange 'heat with one another and that they be dimensionedprop- 'erly with regard to their quantities as required for the various concentration ranges and partial pressure zones.

Fig. 6 shows schematically an absorption refrigerating machine, in which the two closed liquid circuits, whichrun separately.

in the two absorber systems according-to the arrangement of Fig. 2, and one of which includes the range of the mean temperature of the heat'supply, and the other'the range of the high temperature ofthe heat supply,

are combined in Fig- 6 to a common liquid circulating circuit, which passes through the generator andboth absorbers. i

In the same manner the two gas mixture circuits appertaining to the above-mentioned temperature ranges, and which in Fig. 2 form independent closed circuits, are in Fig. 6 also combined to a common gas mixture circulating circuit. whereas the gas mixture circulating circuit between the medium and the low temperature range remains separate. The absorber A in Fig. 6 which is connected to the evaporator E by means of the aforemen-' tion-ed separate gas mixture circulating cir cuit is arranged independent from the absorber A which is connected on its part by means of a gas mixture circulating circuit to sure zone in absorption refrigerating ma-' chines, and for the resorbers in absorption machines, in which heat is produced. Care should be taken, by means of a convenient arrangement of a heat exchanger between the gas mixture flowing to the generator or the resorberand gas mixture flowing from the generator or the resorber, not to have valuable heat carried 05 or to destroy the. cold, It should, however, be observed, that, with the majority of the gas mixture circulating circuits disclosed, the partial-pressure range, which they traverse in two or three difl'erent of both absorption.

- ranges.

For the circulation of the absorption solution various means can be employed, all of which are well known for similar purposes.

If for instance the pressure in the chambers,

where working medium under high pressure is absorbed from the gas mixture, is higher than in the chambers of the same liquid cir culating system, where gaseous working medium is developed out of the absorption solution'into the neutral gas, this difference of pressure can be maintained by means of liquid columns (columns of flowing absorption solution) and a liquid circulating circuit is then established by itself as a result of the difi'erent specific weights of the rich and of the poor solution. In cases in which the sevthe solution in the rising limb of the corresponding U-pipe, which carries the solution for instance into the chamber, which belongs to thehisher temperature range. An example of this type of liquid circulation is given in the arrangement accord ng to Fig. 7, which will be explained in the following.

The absorption machine shown in Fig. 7 is an absorption refrigerating machine of a .tvpe. schemat cally illustrated in Fig- 2.

Similar to Fig. 2, an evaporator and a resorber are provided, and two generators and two absorbers. The evaporator forms with the resorber a liquid circulating system for the absorption solution of the higher concentratlon range. Each of the two generators forms with its respective absorber likewise a liquid circulating system for the absorp tion solution of lower concentration range. The evaporator is connected to one of the two absorbers so as to form .a gas mixture c rculating system. A second gas mixture circulat ng system is provided between the otherabsorber and one of the two generators, and a third gas mixture circulating between the other generator and the resorber. 1 is the generator of the highest partial pressure zone, heated by two heating elements 2. It is of the horizontal type as all other vessels and the inlets for the absorption liquid on the one hand and the gas mixture on the other hand are so arranged in relation to one another, that a counter current of gas mixture and absorption results. The same applies also to all other vessels in which reciprocal efiect takes place between gas mixture and absorption solution. The absorption solution flows from the generator 1 through a U- shaped bent liquid pipe 3 into absorber 4 of the medium partial pressure zone and thence it flows back into the generator 1 by means of a liquid pipe 5 which is in an ex-' change of heat with the pipe 3. The circulation of the absorption is caused by a heating element 6 arranged in the lower part of the rising limb of the pipe 5. The heating element can be connected to an electrical source of energy, for instance to a direct current supply.

In a corresponding manner as the vessels 1 and 4, the generator 8 of the medium partial pressure zone, also heated by heating ele- -ments 7 and the absorber 9 of the low partial pressure zone are connected by means of the liquid pipes 10 and 11, which are in an exchange of heat with one another. 12 denotes here also a heating element, arranged on the rising limb of the U-shaped bent liquid pipe 11- From the resorber 13 the absorption liquid flows through a liquid pipe 14 into the evaporator 15 and thence through the liquid pipe 16, 17, 18 back to the resorber 13. The pipe 16, 1.7, 18 is enlarged in its middle part 17 to a vessel, which surrounds the pipe 14 and forms with the latter a heat exchanger. The part 18 of the liquid pipe which returns the solution from vessel 17 to the resorber 13, forms a U-pipe in the rising limb of which the absorption solution can be heated by means of a heating element 19. The absorber 9 is connected to the evaporator by the gas pipes 20 and 21. The inlets of these vpipes into the gas chamber of the vessels 9 and 15 are placed in. such a manner that,

when selecting an indifferent gas (for instance hydrogen) which is lighter than the gaseous working medium (for instance ammonia), an automatic gas mixture circulating circu t must be brought about as a result of the difference in the molecular weights and as a result of the changes of the specific. weight of the gas columns, caused by the difierence in temperature. The nerator 1 is connected tothe resorber 13 y means of a gas pipe 22, which delivers the gas mixture, enriched with gaseous working medium, to the resorber. Y

For carrying ofi the indifferent gas from the resorber 13,"a gas pipe 23 is provided which ends at thetop of absorber 4. From the absorber 4 a gas pipe 24 runs to the generator 8 and from this generator a gas pipe 25 runs to the top of absorber 4. where it joins the aforementioned gas Dine 9.3. A

' sincevessels 1 and 8 lie in the highest range of temperature of the absorption machine, the rising of the gas mixture to the higher situated resorber 13 or absorber 4 will be favoured by the heating which the gas mix- .ture experiences. The gas current which flows upward through the pipe is divided into two parts. One partflows through the pipe 26 to the generator 1, pipe 22 and resorber 13 the pipe 23, into the other part flows directly to absorber 4, at the top of which it again joins the part flowing through pipe 23. In this manner a greater amount of gas mixture circulates through the vessels 4 and 8 than through the ve'ssels'l and 13.

Besides this particular illustrated example of a. combination of several mixture cycles, a number of other modifications of the invention possible in' this respect, and which refer to the combination of several closed gas mixture circuits'into a common gas mixture circulating system.

It can for'instance also be of advantage in the case of an absorption refrigerating machine which possesses, as illustrated in 'Fig. 4, two generators and. two absorbers but only one evaporator and one resorber to combine the generator of the highest pressure stage, operating without admixture of the indifierent gas (such asK in Fig. 4) with the second enerator and both absorbers to a liquid circu ating system, which is completely separated from the liquid circulating circuit, in which liquid of the other concentration range circulates. In this case itis possible to form in a convenient manner two gas mixture circulating circuits, separated one from another, of w ich one connects the evaporator and one of the two absorbers with one another in the low partial pressure zone,

whereas the other includes both absorbers as well as the generator of the middle partial pressure zone.

If in the above mentioned examples three ranges of temperature are involved, between which the absorption solutions or gas mixtures circulate, the systems according to the invention are not, however, limited thereto.

As it is possible without difiiculty for two 'difierent evaporator temperatures or two entirely different generator temperatures of the heat abstraction to coexist, other ranges of temperature can be easily added'to those already described, in which a reciprocal effect takes place between the absorption and the gas mixture. This improvement may be under certain circumstances of great im ortance if, for instance, by adding the t ird pressure zone the normal evaporator temperature is too low but a portion of the cold maybe produced at a somewhat lower temperature.

Such is the case for instance with a domestic refrigerator where the cooling of the cooling chamberoccurs' a temperature of2 to 4 centigrades above zero, but where a temperature of at least 5 centigrades below zero :must be produced in the evaporator-for the production of ice. One evaporator can be then operated for instance at a temperature of 8 centigrades below zero, the I other at a temperature of zero centigrade. In this case therefore we deal with four ranges of temperature.

If it is, however, of importance to lower the temperature slightly for the production of cold or to considerably reduce the generator temperature,'the intended effect may be obtained by adding another pressure or partial pressure zones s0 fas as it lies within the limits of possibility, whichv are fixed by the physical solutions.

I claim as my invention:

1. In an absorption machine containing a working medium, a solvent for said medium and an indifferent gas not absorbable by said solvent, a generator system comprising at least one generator for developing gaseous medlum from absorption solution concentration range, a resorber system compr sing at least one resorber for absorbing said developed gaseous medium into absorption solution of a second concentration range, an evaporator for evaporating working medium from the absorption solution of the second concentration range, an absorber for absorbing evaporated gaseous medium to form absorption solution of the first concentration range, pipes connecting the a orementioned elements to form a closed circ lation system for said working medium, con ecting pipes between the generator system nd said absorber to permit circulation of th absorption the absorption solution of the second concentration range, the evaporation of working medium in the evaporator, and the absorption of 'aseous medium in the absorber occurring in t e presence of said indifierent gas, the development of gaseous medium from absorption solution of the first concentration range occurring in at least a portion of the genera- -torsystem in the presence of indifferent gas.

2. In an absorption machine containing a working medium, a solvent for said medium properties of the absorption and an indifferent gas not absorbable by said solvent, a generator system comprising at least one generator for developing gaseous medium from absorption solution of a first concentration range, a resorber system comprising at least one resorber for absorbing said developed gaseous medium in absorption solution of a second concentration range, an evaporator for evaporating working medium from the absorption solution of the second concentration range, an absorber for absorbing evaporated gaseous medium to form absorption solution of the first concentration range, pipes connecting the individual parts of the absorption machine to form a closed circulation system for said working medium, connecting pipes between said generator system and said absorber to permit circulation of the absorption solution of the first concentration range, connectin pipes between the said resorber system an said evaporator to permit circulation of the absorption solution of the second concentration range, the evaporation of working medium in the evaporator and the absorption of gaseous medium in the absorber occurring in the presence of said indifferent gas, the development of aseous medium from absorption solution 0 the first concentration range in the generator sys-. tem occurring in the presence of indifierent gas, and connecting pipes between at least a portion of the generator system and at least a a portion of said resorber system to render possible circulation of the indifferent gas throulgh a generator and a resorber.

3. 11 an absorption machine containing a working medium, a solvent for said medium and an indiflerent gas not absorbable by said solvent, a generator system comprising at 40 \least one generator for developing gaseous medium from absorption solution of a first concentration range, a resorber system comprising at least one resorber for, absorbing said developed gaseous medium in absorption solution of a second concentration range, an evaporator for evaporating working medium from the absorptlon solution of the second concentration range, an absorber for absorbing evaporated gaseous medium to form absorption solution of the first concentration range, pipes connecting the individual parts of the absorption machine to form a closed circulation system for said working medium, connecting pipes between said generator system and said absorber to form a closed circulating system for the absorption solution of the first concentration range, connecting pipes between the said resorber system and said evaporator to form a circulatlng system for the absorption solution of the second concentration range, the evaporation of working medium in said evaporatonand'the absorption of gaseous mediumin said absorber oc-- from absorption solution of the first concentration range in at least a part of said generator system occurring in the presence of indifi'erent as, and connecting pipes between that part 0 said generator system and said absorber to permitcirculation of the indifierent gas through said part of the generator system and the absorber.

4. In an absorption machine containing a working medium, a solvent for said medium and an indifferent 'gas not absorbable by said solvent, a generator system comprising at least one generator for developing aseous medium from absorption solution 0 a first concentration range, a resorber system comprising at least one resorber for absorbing said developed gaseous medium in absorption solution of a second concentration range, an evaporator for evaporating working mediumfrom the absorption solution of-the sectration range, pipes connecting the individual parts of the absorption machine to form a. closed circulation system for said working medium, connecting pipes, between said generator system and said absorber to permit circulation of the absorption solution of the first concentration range, connecting pipes between said resorber system and said evaporator to permit circulation of the absorption solution of the second concentration range, the evaporation ,of working medium in said evaporator and the absorption of gaseous medium in said absorber occurring in the presence of said indifferent gas, the development of gaseous medium from absorption solution of the first concentration range in at least av part of said generator system occurring in the presence of indifferent gas, and connecting pipes between said part of the generator system, said resorber and said absorber to render possible a circulation of the indifierent gas through said generator part, said resorber and said absorber:

5. In an absorption machine containing a I said developed gaseous medium in absorption solution of a second concentration range, an evaporator for evaporating working medium from the absorption solution of the second concentration range, an absorber for absorbing evaporated gaseous medium to form ab sorption solution of the first concentration range, pipes connecting the individual parts of the absorption machine to form a closed circulation system for said working medium,

connecting pipes between said generator system and said absorber to permit circulation of the absorption solution of the first concentration range, connecting pipes between said resorber system and said evaporator to permit circulation of the absorption solution of the second concentration range, the evaporation of working medium in the evaporator, and the absorption of gaseous medium in the absorber occurring in the presence of said indiflerent gas, the development of gaseous medium from absorption solution of the first concentration range in at least a part of said generator system occurring in the presence of indifierent gas, and connecting pipes between said part of the generator system, said resorber system, said evaporator and said absorber for establishing a uniform circulation of the indifferent gas through said vessels.

6. In an absorption machine containing a working medium, a solvent for said medium and an indifferent gas not absorbable by said solvent, a generator system comprising at least one generator for developing gaseous medium from absorption solution of a first concentration range, aresorber system comprising at least one resorber for absorbing said developed gaseous medium in absorption solution of a second concentration range, an evaporator for evaporating working medium from the absorption solution of the second concentration range, an absorber for absorbs ing said evaporated gaseous medium to form absorption solution of the first concentration range, pipes connecting individual parts of the absorption machine to form a closed circulating system for the said working medium, connecting pipes between said generator system and said absorber to permit circulation of the absorption solutionrof the first concentration range, connecting pipes between said resorber system and said evaporator to permit circulation of the absorption solution of the second concentration range, the evaporation of working medium in the evaporator, and the absorption of gaseous medium in the absorber occurring in the presence of said indifi'erent gas, the development of gaseous me dium from absorption solution of the first concentration range in at least one generator of said system occurring in the presence of indifferent gas, connecting pipes between said generator, said resorber system and said absorber to form a circulating system for the indiiferent gas through aforesaid elements, said generator system having a second generator free of indifierent gas, and connected in the path of circulation of absorption solu tion of the first concentration range.

7. In an absorption machine containing'a working medium, a solvent for said medium and an indifierent gas not absorbable by said solvent, a generator system comprising at least one generator for developing'gaseous medium from absorption solution of a first concentration range, a resorber system comevaporator for evaporating working medium.

from the absorption solutionof the second concentration range, an absorber for absorbing evaporated aseous medium in absorption solution of t e first concentration range, pipes connecting the aforesaid parts to form a closed circulation system for said working medium, connecting pipes between said generator system and said absorber to permit circulation of the absorption solution of the first concentration range, connecting pipes between the said resorber system and said evaporator to permit circulation of the absorption solution of the second concentration range, the evaporation of gaseous medium in the evaporator and the absorption of gaseous medium in the absorber occurring in the presenceof said indifii'erent gas, the development of gaseous medium from absorption solution of the first concentration range in at least a portion'of said generating system occurring in the presence of indifferent gas, the development of aseous medium in the generator system ,nd its conversion into a more dense fluid phase occurring at a partial pressure higher than the partial pressures of 'the gaseous working medium in the other vessels.

8. In an absorption machine containing a working medium, a solvent for said medium and an indifferent gas not absor'bable by said solvent, a generator system comprising at least one generator for developing gaseous medium from absorption solutionof a first concentration range, a resorber system comprising at le'ast'one resorber for absorbing the developed gaseous medium in absorption solution of a second concentration range, an evaporator for evaporating working medium from the absorption solution of the second concentration range, an absorber for absorbing evaporated gaseous medium in absorption solution of the first concentration range, pipes connecting the aforementioned parts to form a closed circulation system for the said working medium, connecting pipes between said generator system and said absorber to per- 'mit circulation of the absorption solution of the first concentration range, connecting pipes between the said resorber system and said evaporator to permit circulation of the absorption-solution of the second concentration range, the evaporation'o'f working medium in the evaporator and the absorption of gaseous medium in the absorber'occurring in the presence of said indifi'erent gas, the development of gaseous medium from absorption solution of the first concentration range in at least a portion of said generator system occurring in the presence of indifferent gas, the development of gaseous medium in the generator system, and its conversion into a more dense fluid phase occurring at a partial pressure higher than the partial pressures of the gaseous working medium in the other vessels, and said gas development occurring at a higher temperature than the gas development and absorption in the other vessels.

9. An absorption machine having a generator for developing gaseous working medium from an absorption solution of a first concentration range, an absorber for absorbing working medium by an absorption solution of the same concentration range, a second generator and a second absorber for respectively developing working medium from, and absorbing it into absorption solution of a second concentration range, an evaporator for evaporating working medium from absorption solution of a third concentration range, a resorber for absorbing said evaporated medium to form absorption solution sorbers, evaporator and resorber having an indifferent gas admixed to it, connecting pipes between the said first generator and said resorber, connecting pipes between said second generator and said first absorber and between said second absorber and said evaporator to form gaseous mixture circuits through the vessels connected with one another.

10. An absorption machine, containing a generator and an absorber, a second generator and a second absorber, an evaporator and a resorber, said first generator being connected with said first absorber, said resorber and said evaporator so as to form a common circulation circuit for absorption solution, said second generator being connected with said second absorber to form a second circulation circuit for absorption solution, the gaseous working medium in the said two absorbers, the said second generator and the said evaporator having indifferent gas admixed to it, and connecting pipes between the said last named vessels to permit circulation of indifferent gas through them.

. 11. An absorption machine for the production of heat of high temperature, containing a generator, an absorber, an evaporator and a resorber, connecting pipes between said vessels to permit circulation of absorption so- I lution through them, the gaseous working medium in said vessels having an indifferent gas admixed to it, and further connecting pipes between the said vessels to permit circulation of indifferent gas through said generator, resorber, absorber and evaporator.

12. An absorption refrigerating machine, containing a. generator andan absorber, a second generator and a second absorber, an evaporator and a resorber, connecting pipes between said evaporator and resorber to permit circulation of absorption solution through said two vessels, connecting pipes between said two generators and said two absorbers to permit circulation of absorption solution through the last-named vessels, the gaseous working medium in said evaporator and in one of the two absorbers having indifferent gas admixed to it, the gaseous working medium in said second generator and in the other of the two absorbers having indifferent gas admixed to it, and connecting pipes within the two groups of vessels to establish two circuits for the gas mixture, one through said evaporator and one of said absorbers, and the other through said other absorber and said generator.

13. An absorption refrigerating machine containing a generator, a resorber, an evaporator and two absorbers, connecting pipes between said evaporator and said resorber to permit circulation of absorption solution through said last-named vessels, connecting pipes between said generator and said absorbers to permit circulation of solution through said generator and said absorber, the gaseous working medium in all said vessels having indifferent gas admixed to it, connecting pipes between said evaporator and one of said absorbers to establish circulation of indifferent gas through said last-named vessels, connecting pipes between said generator, said resorber and said other absorber to establish circulation of indifferent gas through said generator, said resorber and said absorber.

14. An absorption refrigerating machine having several different partial pressure zones in its constituent vessels and containing two generators, a resorber, an evaporator and two absorbers, one of said generators and said resorber belonging to a high partial pressure zone, and one of said absorbers and said evaporator belonging to a low partial pressure zone, while the other generator and the other absorber belong to a medium partiaI pressure zone, connecting pipes to permit circulation of absorption solution between said resorber and said evaporator, connecting pipes for establishing a second solution circuit including said first generator and said second absorber, and connecting pipes for establishing a third solution circuit including said second generator and said first absorber,'the gaseous working medium in all of said vessels having indifferent gas admixed to it, connecting pipes between said evaporator and said first-mentioned absorber for establishing circulation of gas mixture through the lowest partial pressure 'zone vessels, connecting pipes between said second generator and said second absorber for establishing circulation of gas mixture through the medium partial pressure zone vessels, connecting pipes between said first generator and said resorber for establishing circulation of gas mixture through the highest partial pressure zone vessels, and an intermediate connection between the gas circulation systems of the highest and of the medium partial pressure zone, whereby the amount of sorber and said evaporator, connecting'pipes .for establishing a second liquid circuit between said first generator and said second absorber, and connecting pipes for establishing a third liquid circuit between said second generator and said first absorber, the gaseous working medium in all of said vessels having indifferent gas admixed to it, connecting pipes between said evaporator and said first-mentioned absorber for establishing circulation of gas mixture through the 7 lowest partial pressure zone vessels, connecting pipes between said second generator and said second absorber for establishing circulation of gas mixture between the medium artial pressure zone vessels, connecting pipes between said first generator and said resorber for establishin circulation of gas mixture between the highest partial pressure zone vessels, and an intermediate p1pe connection between the gas circulation systems of the highest and the medium partial pressure zone, whereby a reciprocal action occurs between the absorption solution and the total amount of indifierent gas mixture in the medium partial pressure zone, but whereby only a portion of this total amount takes part in the reciprocal action with vabsorption solution in the highest partial pressure zone, in cluding the first generator and the resorber.

16. An absorption refrigerating machine,

gaseous working medium in all of said vessels 4 v aving indifi'erent gas admixed to it, connecting pipes between said evaporator and said first-mentioned absorber for establishing circulation of gas mixture through the lowest partial pressure zone vessels, connecting pipes between said second generator and said second absorber for establishing circulation of gas mixture through the medium partial pressure zone vessels, connecting pipes between said first generator and sa1d resorber for establishin mixture through the hig est artial pressure zone vessels, and an interme 'ate connection between said gas circulation systems of the highest and the medium partial pressure zone, whereby the amount of mixture flowing through one zone is difi'erent from the amount flowing through the other zone, all liquid circulation pipes between the vessels of the several aforestated groups being U-shaped and disposed in heat exchanging relation to one another to circulate absorption solution be tween the vessel situated in a higher temperature range and the vessel situated in a lower temperature range, and a heating element in each group of pipes attached to the upwardly extending leg of the U-pipe leading to the higher temperature vessel for heating the absorption liquid in said le In testimony whereof I afl ix my signature.

EDMUND ALTENKIRCH.

having several different partial pressure zones in its constituent vessels, and containing two generators, a resorber, an evaporator and two absorbers, one of said generators and said resorber belonging to a high partial pressure zone, and one of the two absorbers and said evaporator belonging to a low partial pressure zone, while the other generator and the other absorber belong to a medium partial pressure zone, connecting pipes to permit circulation of absorption liquid between said resorber and said evaporator, connecting ipes for establishing a second liquid circuit tween said first generator and said second absorber, and connecting pipes for establishing a third liquid circuit between said second generator and said first absorber, the

circulation of gas 

